Process for obtaining halogen derivatives of indigo and of its homologues



' dyes.

" NIT-ED sure-is PAfIiE N T" I 1 MAURICE BOUIVIER, or Lyon, FRANCE, ASSIG-KORJDOSOGIETE summon nns'nsmns DU RHONE, ANCIENNEMENT GILLIARD'EP. :moamnr {ET pew-men, .OE'JIEARIS,

FRANGE.

PROCESS FOR OBTAINING HALOGEN V ,LoorUEs.

No Drawing.

ToaZZ whom it may concerm Be it known that I, MAURIGEBOUVIER, a citizen of the Swiss Republic, of. 25Co'urs Gambetta, Lyon, France, have invented a certain new and useful Process for Obtaining'Halogen Derivatives of Indigo-and of Its Homologues, of which'the following isa specification.

This invention relates to processes for Ohtaining halogen derivatives of indigo and of-its homologues for use as colorants "or i The object of the invention'is to provide a process of the kindindicated, wherebythe output of halogenated indigo is improved both as to quantity for agiven expenditure of materials and also as to the quality ofthe colorants obtained. o

i As is well known, halogens'react on indigo and its honiologues either directly or in the presence of suitable solvents. The substitution 18 more or less complete according as the operation is carried out at a higher low temperature and it is also greatly influenced by "the'nature ofthe solvent. Several processes have heretofore been proposed comprising the employment as solvent, of sulphurio chlorhydrin (chlorosulphonic ,acid) either alone or mixed with fuining sulphuric acids. "The use of sulphuric ,chlorhydrin is advantageous inrmany respects, but it has a great disadvantage especially in the preparation of derivatives which are not completely halogenated; /Vhenbroinine, for instance, acts on indigo inthe'presence of sulphuric *chlorhydri'n, hydrobromic acid re sults, which is oxidized intoibromine; water is formed, and this in turnreacts on'the ohlorhydrin and decomposes w it into sulphuric-and hydrochloric acids.

DERIVATIVES or mnrqo Ann ion ris omo- Specifieation of Letter sJ-atents I cPtlateIl-t/Bd ,May2, 1922.

Application filed October 1, 1918; .Serlal No. 256,4?)0. v

so' -nown ozi-iuso noi 5 se saw-rus :so +Ho1+B +11 0 IThe reaction takes place as-if this nascent" sulphuric acid sulphonated the indigo and theoutputof halogenated indigoinsolublein our textile fibres in t'ints much less pure and I less vivid than the correspondingly halogenated indigos prepared by other processes;

It is .possible,'up, to a certain point, to

counteract this disadvantage by employing a large expess'of bromine but this'int-roduces a fresh diflioulty, the sulphonation is some what-prevented butit is very difiiculttoim troduce into the molecule of indigo-the necessary opuantity of bromine for obtaining the desired halogenated-derivative.

In the process .accordingto this invention, the iforrnation of nascent sulphuric acid 'is' avoided during the bromination ofthe indigo r and, of,its zhor n ologues in sulphuric chlorhy drin, by causing the said. bromination to take place iuthe presence of a substance having a; greater afiiriityfor water than sulphuric anhydride. 0f the substances which possess this property, phosphoric pentoxideis particularly advantageous as it dissolves perfectly in Sulphuric:chlorhydrin, and durv eHG eB -zwrog i Sulphurous anhydrid is thus liberated and 'ing 'the bromination, it absorbs the Water one half less of hydrochloric acid than would havebeen liberated in the absence of the phosphoric pentoxide or the likesubst ance.

This process is applicable to all the brominated derivatives of indigo and of its homologucs as well as to the mixed halogenated derivatives. 1

In order that the nature of the invention may be well understood, the application of the process in accordance therewith .will now The temperature is allowed to riseduring the space oi. two-hours to C. and the mixture is stirred during 7 hours at this temperature. f j

The mixture is then poured on to ice, and

" the colouring matter thus obtained is filtered and washedJconsistingi of pure tetrabromindigo which is in all probability the 5-7-5-7 tetrabromindigo. The dyes obtained by this product are more beautiful, more vivid, and. fresher looking than these produced by tetrabromindigo prepared without the use of phosphoric pentoxide.

It is also possible to obtain very good resultsby first placing the dibromindigo in the apparatus and'then pouring iii-slowly the mixture previously prepared and cooled oi. sulphuric chlorhydrin, phosphoric pentoxidei, and bromine.

V trample-Il.-Tribr0m0-0-t0ZyZindig0.

In an -apparatus provided witha mixer, are placed. 15.5 parts of sulphuric chlorhydrin, one part of bromine and 0.5 part [of phosphoric pentoxide This is cooled to -5, or as far as -l0 C. and during a period of 15 minutes-5.6 parts of dibrominated.o-tolylindigo i.e., 7-7 dimethyl-5-5-dibromind-igo (1 molecule) are added. j v

The-temperature is then allowed to rise to 0 C. during a spacefof two hours and f filtered and washed.

the mixture 'is stirred at this temperature during 5 hours more, after which it is poured on to pounded ice and diluted with water. The colouring matter is precipitated, then The tribominated -0-tolylindigo thus obtained is a powder of a fine blue violet colour; it is easily reduced by alkaline hydrosulphit-e to a yellow greenish vat and dyes cotton to a very pure blue considerably more vivid and of a more reddish colour than that obtained by the dibrominated o-tolylindigo. a v Example [[1 .T 6 25m bromo-o-tolylindigo.

The process is similar to that just described in ExampleII but the proportions are 7.8 parts of sulphuric chlorhydrin one part bromine (1 molecule) 1 part of phosphoric pentoxide. This solution is cooled down to 5 or as far as 10 C. whereupon for half an hour 2.8 parts of dibromo-o-tolylindigo (1 molecule) are added little at a time. The temperature is then allowed to rise to 20 C. for three hours, and for six hours more the mixture is'stirred at this temperature. The

mass isthen poured on to pounded ice when the colouring matter is precipitated.

. It contains a proportion of bromine corresponding to tetrabromo-o-tolylindigo V and somewhatresembles the tribromo derivative giving a greenish yellow vat which dyes cotton to a very line and pure v reddish blue.

In Examples II, and III, it is understood that one can start from ortho-tolylindigo itself or from any one of its halogenated derivatives to obtain compounds more highly Greater or lesser quantities of halogenated. the halogen (bromine) will in this case be introduced into the combination, and the quantity of phosphorous pentoxide required will be simultaneously varied. It will be seen that mixed halogenated compounds may readily be obtained in starting, for instance, from the chlorinated derivatives of o-tolylindigo and in brominating theiniby the process justindicated; in this case, more or less of the halogen will be introduced and the I same time the quantity of phosphoric an hydride will be varied. V 1

The mixed brominated derivatives canalso be "obtained by this process and, instead of bromine, substances such as alkaline bromides which'produce bromine in the presence of sulphuric chlorhydrin may be employed. In eacl1:case, a suitable quantity of phos phoricanhydride will be used. I i

The compounds described in the above Examples II, III, IV, and Vare new and possess great value; when used as dyes their tints are distinct from those of the monoand dihalogenderivatives of o-tolylin digo described in French Patents 32286.4 and 32397 7 in factthe new tints are much richer,

Solution in- 'lribromo-o-tolylindigo. Tetrabromo-o-tolylindigo. Pentabrorno-o-tolylindigo. Hexabromom-tolylindigor Concgntrated sulphuric Green Green Green.... Slightly soluble green.

acr

Hot sulphuric acid Dark green Q Dark green. Dark green... .l Brownish green. Cold aniline Greem'sh blue Greenish blue. Green... Green.

Hot aniline Pinkish pure blue with Pure purplish blue with Reddish blue with slight Reddish blue with slight slight transparency. slight transparency. transparency. transparency. I I Cold nitrobenzeneun n. Slightly greenish blue..... Greenish blue Pinkish green blue with Slightly soluble greenish slight transparency. blue.

Hot nitrobenzene. Pinkish blue with slight Reddish blue with slight Reddish blue with slight Violet blue with slight transparency. transparency. transparency. transparency. V chloroform Purplish blue Blue Slightly soluble b lue...... Slightly soluble greenish g ue.

' Acetone, Purplish blue Blue Very slightly soluble blue. Veryslightly soluble green. Benzene Purplish blue..'. Blue Slightly greenish blue"... Slightly soluble greenish v I V v p 7 I ue' Alcohol Blue Slightly solubleblue Ver iliightlysolublegreen- Veryslightlysolublegreen.

' 1S ue.

'Carbon tetra-chloride... Blue Slightly soluble blue slioglhtly soluble greenish Veryslightly soluble green;

ue. v v

Alkatline hydro-sulphite Greenish yellow Greenish yellow Greenish Greenish.

va v

Dyeing on cotton Reddish bright blue Reddish bright blue Greenish bright blue.;.... Very greenish bright blue.

more brilliant, and purer than those obtained a few of the properties of the newcolouring by the said known compositions.

In the following table are brought together mattersobtained by the present invention:

What I claim and desire to secure by Letin presence of a substance having a greater ailinity for Water than sulphuricanhydride.

2. A process for the manufacture of halogenated derivatives of indigo and its'homologues by brominating the said indigo, its

homologues and its substitution products by means of bromine in sulphuric chlorhydrin in presence of phosphoric pentoxide.

3. The process of manufacturing halogenated derivatives of indigo audits homologues Which consists in mixing together a solution of sulphuric chlorhydrin, phosphoricpentoxide and bromine, stirring the mixture, andadding thereto a derivative of ortho-tolylindigo.

4. The process of manufacturing hal0g-,

enated derivatives of indigo and "its homologues Which consists in mixing together a logues which consists in mixing together a" solution of sulphuric chlorhydrin, phos-' phoric pentoxide and bromine, cooling said 40 mixture to'a temperaturetbetween -5 and a .10 (1., adding thereto a derivative of ortho-tolylindigo, and raisingthe temperature to between 0 and 20 0.

In testimony WhereofI have signed my'45 name to this specification.

MAURICE BOUVIER.

Witnesses MARIN VAOHOR,

L. ERCHER. v 

